Grey Digestor Transportation, Loading & Testing between 27-29 October 2010 (Wed - Friday)

 
Almost done with the construction, what's left is getting the end-caps which are out of stocks, an aerobic stage discharge hose, and a 50 cm stand for brenda.

Enough said; as usual, a picture speaks a thousand words:


Drilling more holes at the base worked; no rainwater collected despite the heavy rain:

Transporting the digestor from Ensure:

Transporting the digestor to Singapore Vision Farm:

The close-up of the loaded digestor sight glass

This is how the digestor looked like from the top; if you climb 2 meters:

Let the test analysis begin!

 

  

Will be scouting for the test chemicals for COD, BOD tests and the thermo-reactor on Monday (1st November 2010) after school.

Results of pH Test

Human Waste: 6.9

Water: 9.0

What else?!?! To recalibrate the pH meter!

Kian How, signing off on 29 October 2010, 9.30pm

Backwashing Valve Purchased & Pre-Run Test Preparations on 26 October 2010 (Tuesday)

 
 
As per planned, Marcus went to Ensure Engineering to deliver the 3/8" backwash valve & fittings to Mr Kannan. Pilot Plant would be fully commissioned and transported to SVF tomorrow at 2pm.

Brenda contacted Drager Company and got a quotation.

KH went to the lab, found the vacuum pump for drager tubes, the colorimeter for ion concentration measurement and the necessary test reagents for the runs tomorrow. To sign out pH meter, DO meter etc:

 

Ready for the big Run for both grey & orange digestors tomorrow at 3pm? Lets go!!!

Kian How, signing off on 26/10/10, 8.10pm.

Grey Digestor Pre-commissioning on 25 October 2010 (Monday)

As per initial plans, spoke to Mr Kannan to finalize digestor construction & design at ENSURE:

1. Grey-D (w/o totaliser & Gas-D) to be commissioned on Wed
2. Vacuum trucked and Forklift booked for Wednesday
3. Buy 3/8" or 1/4 ball valve, nipple + coupling & End-cap for backwash valve; to retain 1/2" sight glass (all sch 80)
4. Buy 2 2" End-caps, 1 1" End-caps (sch 80) + create their respective screwed-on piping ends
5.  Insert PI, Modify aerobic T-vent - buy 1" End-cap (non-screw-on type)
6. Approach Mdm Tan for Photometer - sulphate test chemical
7. Drill holes at base against rain accumulation + Funnel hook
8. Got Brenda to contact Drager Company
9. KH to buy laminating plastic

The Blue & Grey Digestors; Blue for commercialisation, Grey for Testing:

1/2" Sight Glass; yet to insert backwash valve:

The LEAK-PRONE Blue Prototype 1; transported back from Vision Farm (SVF) last friday:

Scrubber Outlet directs water straight to the ground:

Blue-D, bottom issue - under influence of weight, drum base is compressed - initial measurements void. To discuss with Dr Han & design a fool-proof stand:

The incredibly weak drum cap; HDPE-made, unable to support the weight of fittings, giving rise to air-leakage; Dr Han to create an alternative PVC/Metal top with the same dimensions, so that we may "screw-on" the fittings. This design takes into consideration both mechanical strength/integrity and air-leakage:

The condensate drain port for  methane capture commissioned:

On Wed, 27/10/10:

1. Marcus: Load Orange-D at SVF
2. Brenda: Monitor Grey-D transportation at Tuas
3. KH: to join group at SVF once lesson ends
 

On Fri, 19/10/10:

• KH and Brenda to meet Dr Han; Blue-D issues
• Marcus to join us at Sun Hee to purchase fittings (evenings)

Kian How, signing off on 25/10/10, 7.30pm.

Blue-Digestor Reconstruction on 22/10/10 (Friday), 9am-3pm

All in all, we dismantled prototype 1 (blue) & transported it back to ensure engineering. Did purchasing again for blue-D valves and fittings; PVC Cement & Primer; Grey-D aerobic stage bends

Sort of freak accident - the soil softened and barricade collapsed over our lorry - KH & Brenda almost died, click on image to enlarge:

Brenda to call on sat (23/10/10) :

• Dr Han - Blue-D top (air tightness) + bottom (leakage issues)
• Cancel Vac truck appointment on monday
• Taiko for Drums x3
• Book Vac truck for Wednesday
• Book transportation (forklift) for Grey-Digestor for Wednesday

Plan for 25-31 October 2010 (S2 week 1):

Mon:      KH to go ensure to finalise Grey-Digestor design issues with Murugan/Kannan.
Tues:      None; allow ensure to construct Grey-D according to KH's instructions
Wed:      All 3; Transport Grey-D, Load Orange and Grey-D (noon), buy fittings from sunhee (evenings)
Thurs:    Marc & KH; Blue-D building at ensure
Friday:   Brenda & KH; Blue-D building at ensure
Sat & Sun: May go down to ensure, depending on progress

Due to Blue-D's issues & delays; fyp runs limited to:

• Orange-D: 3
• Grey-D: 3
• Blue-D: 2

Each run is estimated at 14 days; 1st Run to commence on 27 October 2010 (Wednesday).

*** KH to get Drager Tubes & Drager pump ***

Kian How, signing off on 22/10/10, 10.20 pm.

Sight Glass Commisioning on 7 October 2010 (Thursday)

The setup with the 1/2" Sight Glass Commissioned; the base repainted in red:

The Turbine Flowmeter/ Totaliser to be inserted at circled region for flow measurements.

Total Length of 2" Double-flanged end totalizer = 15cm, weight = 10 kg - to construct supports and tie in support with gas sampling port:

Close-up of the Burner Section; Design was changed to accommodate the spatial requirements:

As per discussed with Mr Kon, Marcus to do on 11 October 2010 (Monday):

1. Insert 1" Isolation Valve for Anaerobic Stage
2. Change 1/2" to 1" sight glass - go kelantan - resolve plugging issues
3. Insert 1" Cross joint + 1" Ball valve for back-washing
4. Insert wheels on base - for exhibition purposes
5. Check vacuum truck - Load prototype directly from vacuum truck - design quick connection coupling; discuss with Mr Kannan to ensure that digestor can support weight of truck fittings.
6. Approximate concentration in  (5) using densitometer - compare Refractive Index. Check with Dr Han amount of water used per flush in SVF to further verify waste concentration.
7. Change KH's tee-joint Receipt - from September to October for claiming
8. Buy 1" sch 80 end cap x6; do not thread aerobic outlet
9. Gas Sampling Port - 6cm tip - wait for gas detector arrival
10. Totaliser - 2 alternatives - budget < $1000

• 2" Flange end design - contact Mr Kannan ASAP
• KH to call Auric - backup
• Follow up on Endress

Updated pfd With:

1. Methane Capture Condensate Drain valve - accumulation of wet gas from scrubber
2. Back-washing valve for 1" sight glass - plugging of manure/ tissue papers

Kian How, signing off on 8 October 2010, 3 pm.

Prototype 2 Construction Progress - Piping's Up on 6 October 2010 (Wednesday)

A picture speaks a thousand words; click on image to enlarge.

In summary, the main piping and valve connections are up, less the sight glass as we were short of a 1" x 1/2" Reducer Bushing. The workers used metal and I explained to them that metal can't be used - detrimental to methanogens etc. Hence, I will need to do more purchasing tomorrow. Due to the lack of manpower, me and marcus will work on 2 separate sites:

Kian How - Tuas:

• Buy 1" x 1/2" PLASTIC Reducer Bushing x1
• Buy 1" threaded sch 80 End Cap x3
• Buy 2" threaded sch 80 End Cap x1
• Buy 2" Hose Ring x1
• Drill holes on base - to prevent rain water accumulation
• Supervise construction of bushing for gas sampling port
• Call Ai Ling (Auric) for Detailed Gas-D Sampling Probe Dimensions

Marcus - SVF:

• Meet Vacuum Truck at 10.30am
• Run Orange Digestor
• Draw out a table of data to record (Temp, pH, age of input waste, etc)
• Follow up on Totalizer

Auric Gas Detector Sampling Probe - KH to call Auric for dimensions to construct sampling port:

Kian How, signing off on 06/10/10, 9.30 pm

Prototype 2 Construction Progress on 5 October 2010 (Tuesday)

As all the valves and fittings bought were threaded to ensure air-tight conditions, the pipes had to be threaded as well. An experienced operator would take about 30mins per threading process.

We have a total of 20 valves + more fittings, threading on both sides, calculate yourself the amount of time taken to complete the threading x2. The whole day was pretty much about threading the pipes.

This is the threading machine:

The close-up of a threading machine; the pipe is first clamped onto a metal disc for further cutting:

Video Clip of the tedious and cumbersome threading process:

The above threading process is a process of "agar-ration", wherein the operator runs the machine and attempts to "cut out" the desired thread lining till it fits the valve perfectly. If the 1st run does not fulfill the requirement, deeper threads are made and process is repeated till it fits the valve snugly.


Combination of threading and PVC Cement:

 

The excess PVC cement was "forced/ squeezed" out of the pipes, making it function like a silicon sealant, ensuring air-tight conditions:

This was how the interior of the aerobic stage looked like, without tightening the flange yet:

This is the agitator. Unfortunately, the supporting rods were made of metal; we got the workers to redo it. Metal are detrimental to the growth of fermentative microbes. All my conflict management and communication skills really came into play...

The Burner Section:

Left:       P&ID View
Middle:   Unassembled Fittings and parts
Right:     Assembled & Completed Burner Section.


Look at the difference between the 3 diagrams, it looks simple on paper, just tee-joints and valves. In the actual thing, nipples - 8 of them are required - this explains the cost and the time taken to do purchase, even with much deliberate planning. It's somewhat amazing that these 20+ fittings only amount to one small burner section of the digestor.


All I can say is: "Welcome to the real world !!!"


Kian How, signing off on 6 October 2010, 12.30 pm

More Purchasing on 4 October 2010, Monday

Despite initial plans, we were still short of many fittings. We almost got scammed:

• 2" PVC End Cap, Threaded = $13 - this can get us a 2" ball valve
• 1" PVC End Cap, Threaded = $9

Of course, we did not purchase the End Caps ultimately - went to Sun Hee instead. It's one of the 3 locations (and more organized stalls) we went to, but searching high and low in a  stall like this below pretty much summed up one frustrating/ exhausting day:

Look at the receipts below, if one fitting takes 15 minutes to locate, you will probably understand our frustrations.

 

Kian How, signing off for 4th October Updates

The 4 Main Chambers & Fittings

The 4 mains chambers up with major fittings purchased
(1st October 2010, Friday)

Minor Changes made to PFD Below:

1. Scrubber bypass inserted to test for H2S Removal with and without scrubber
   (compare with September post)
2. Repositioning of CV on center 1" pipe to permit gas flow.
3. All parts after methane capture to be made of metal.

The 4 main chambers are up:

All the valves and fittings I & Marcus have bought within the last week
(estimated costs = $500):

The 2 cans on the bottom left depict PVC Cement; an industrial grade glue (2 types) used to provide air-tight sealing and mechanical strength. - Apply glue one 1st, then use glue 2 to "force" glue 1 inwards the pipes.




The picture below depicts "level gauge valves". Rather than using multiple valves, pipes and tee-joints to create a sight glass (see tube right of anaerobic stage), the 4-way valves below comes in a pair (top and bottom for sight glass) reduces the length of piping connection. Downside: 1 set costs $170. The group went against the idea of using these valves as the metallic parts have adverse efftects on fermentative bacteria growth; unfortunately, PVC-type Level Gauge valves are not available in the market.

 

The group happened to stumble upon this flight of steps; we had always wanted to steps to be attached to the digestor to facilitate easy loading, but Dr Han explained it was to costly. If these steps are "unwanted", we would be integrating them as part of the digestor - awaiting Dr Han's reply.

  

Attempted to climb it; it was extremely stable; loading port may be easily reached, even for Brenda's height.

Plans for 04/10/10 to 10/10/10:

Monday:

1. PI Connectors x2
2. 1" x 3/4" Reducers for Sight Glass x2
3. Threaded N-caps for outlets/inlets
4. U-bends for Check valves x2 - Check if blocking reducers
5. 90 degrees metal elbow for PSV outlets x2 - Rain protection
6. KH to contact Citigas for Totaliser
7. To fully construct system
8. Contact Vacuum Truck
9. Uncle Chris to store Waste from Camp

Tuesday:

1. To transport prototype 2 to SVF
2. Orange Digestor Loading
3. Prototype 2 Loading - Read operating Procedure

As Individuals:

• KH: Lit Review
• Marcus: H2S investigation
• Brenda: Sketch-ups, SG Map & Logbook

Kian How, signing off at 5.45 pm, 02/10/10.